Zhang Qijia, Xu Guangda, Guo Na, Wang Tongtong, Song Peng, Xia Lixin
College of Chemistry, Liaoning University, Shenyang 110036, China.
Yingkou Institute of Technology, Yingkou 115014, China.
Materials (Basel). 2021 Oct 1;14(19):5750. doi: 10.3390/ma14195750.
The purpose of this study was to develop a flexible substrate methylcellulose-decorated silver nanoparticles (MC/Ag NPs) film and explore its application in fruits and vegetables by surface enhanced Raman spectroscopy (SERS) technology for rapid detection of pesticides. The performance of the MC/Ag NPs film substrate was characterized by Nile blue A (NBA), and the detection limit was as low as 10 M. The substrate also exhibited satisfactory Raman signal strength after two months of storage. The impressive sensitivity and stability were due to the excellent homogeneity of the silver nanoparticles that were grown in situ in the methylcellulose matrix, which generated "hot spots" between the silver nanoparticles without a large amount of aggregation, and resulted in the ultra-high sensitivity and excellent stability of the MC/Ag NPs film substrate. The MC/Ag NPs film substrate was used to detect thiram pesticides on tomato and cucumber peels, and the minimum detectable level of thiram was 2.4 ng/cm, which was much lower than the maximum residue level. These results indicate that the MC/Ag NPs film is sensitive to rapid detection of multiple pesticides in food.
本研究的目的是制备一种柔性基底甲基纤维素修饰的银纳米颗粒（MC/Ag NPs）薄膜，并通过表面增强拉曼光谱（SERS）技术探索其在水果和蔬菜中快速检测农药的应用。用尼罗蓝A（NBA）对MC/Ag NPs薄膜基底的性能进行了表征，检测限低至10 M。该基底在储存两个月后也表现出令人满意的拉曼信号强度。令人印象深刻的灵敏度和稳定性归因于在甲基纤维素基质中原位生长的银纳米颗粒具有优异的均匀性，其在银纳米颗粒之间产生了“热点”，而没有大量聚集，从而导致MC/Ag NPs薄膜基底具有超高的灵敏度和优异的稳定性。MC/Ag NPs薄膜基底用于检测番茄和黄瓜表皮上的福美双农药，福美双的最低可检测水平为2.4 ng/cm，远低于最大残留限量。这些结果表明，MC/Ag NPs薄膜对食品中多种农药的快速检测具有敏感性。
